Fluid pumps and related systems and methods

ABSTRACT

A reciprocating fluid pump includes a pump body, a first subject fluid chamber, a second subject fluid chamber, a first plunger at least partially defining a first drive fluid chamber and including a flexible material and configured to expand and compress in a reciprocating action to pump the subject fluid through the first subject fluid chamber within the pump body, and a second plunger located within the pump body and at least partially defining a second drive fluid chamber and including a flexible material and configured to expand and compress in a reciprocating action to pump the subject fluid through the second subject fluid chamber within the pump body, wherein the first plunger is not structurally coupled to the second plunger, such that the first plunger and the second plunger are independently movable during operation.

TECHNICAL FIELD

Embodiments of the present disclosure relate generally to reciprocating fluid pumps that include a reciprocating plunger, to components and devices for use with such pumps, and to methods of using such reciprocating fluid pumps and devices.

BACKGROUND

Reciprocating fluid pumps are used in many industries. Reciprocating fluid pumps generally include two fluid chambers in a pump body. Typically, a reciprocating piston or shaft is driven back and forth within the pump body. Conventionally, one or more plungers (e.g., diaphragms or bellows) are connected to the reciprocating piston or shaft. As the reciprocating piston moves in one direction, the movement of the plungers results in fluid being drawn into a first fluid chamber of the two fluid chambers and expelled from the second chamber. As the reciprocating piston moves in the opposite direction, the movement of the plungers results in fluid being expelled from the first chamber and drawn into the second chamber. A chamber inlet and a chamber outlet may be provided in fluid communication with the first fluid chamber, and another chamber inlet and another chamber outlet may be provided in fluid communication with the second fluid chamber. The chamber inlets to the first and second fluid chambers may be in fluid communication with a common single pump inlet, and the chamber outlets from the first and second fluid chambers may be in fluid communication with a common single pump outlet, such that fluid may be drawn into the pump through the pump inlet from a single fluid source, and fluid may be expelled from the pump through a single pump outlet. Check valves may be provided at the chamber inlet and outlet of each of the fluid chambers to ensure that fluid can only flow into the fluid chambers through the chamber inlets, and fluid can only flow out of the of the fluid chambers through the chamber outlets.

BRIEF SUMMARY

In some embodiments, the present disclosure includes a reciprocating fluid pump for pumping a subject fluid. The reciprocating fluid pump can include a pump body, a first subject fluid chamber within the pump body, a second subject fluid chamber within the pump body, a first plunger located at least partially within the pump body and at least partially defining a first drive fluid chamber, the first plunger comprising a flexible material and configured to expand and compress in a reciprocating action to pump the subject fluid through the first subject fluid chamber within the pump body, and a second plunger located at least partially within the pump body and at least partially defining a second drive fluid chamber, the second plunger comprising a flexible material and configured to expand and compress in a reciprocating action to pump the subject fluid through the second subject fluid chamber within the pump body. The reciprocating fluid pump may further include a first sensor assembly at least partially disposed within the pump body and configured to sense a position of the first plunger, a second sensor assembly at least partially disposed within the pump body and configured to sense a position of the second plunger, and an external controller operably coupled to the first sensor assembly and the second sensor assembly and configured to insert drive fluid into the pump body based on sensed positions of the first plunger and the second plunger, wherein the first plunger is not structurally coupled to the second plunger, such that the first plunger and the second plunger are independently movable during operation

In one or more embodiments, the present disclosure includes a reciprocating fluid pump for pumping a subject fluid. The reciprocating fluid pump may include a pump body, a first subject fluid chamber within the pump body, a second subject fluid chamber within the pump body, a first plunger located at least partially within the pump body, the first plunger including a flexible material and configured to expand and compress in a reciprocating action to pump the subject fluid through the first subject fluid chamber within the pump body, and a second plunger located at least partially within the pump body, the second plunger including a flexible material and configured to expand and compress in a reciprocating action to pump the subject fluid through the second subject fluid chamber within the pump body. The reciprocating fluid pump may further include a first drive fluid chamber at least partially defined within bellows of the first plunger, a second drive fluid chamber at least partially defined within bellows of the second plunger, a first piston chamber formed within the pump body and adjacent to the first drive fluid chamber, a second piston chamber formed within the pump body and adjacent to the second drive fluid chamber, a first piston coupled to the first plunger and extending between the first drive fluid chamber and the first piston chamber, the first piston comprising a first plurality of vents extending through the first piston and from the first drive fluid chamber to the first piston chamber, and a second piston coupled to the second plunger and extending between the second drive fluid chamber and the second piston chamber, the second piston comprising a second plurality of vents extending through the second piston and from the second drive fluid chamber to the second piston chamber.

Some embodiments of the present disclosure include a reciprocating fluid pump for pumping a subject fluid. The reciprocating fluid pump may include a pump body, a first subject fluid chamber within the pump body, a second subject fluid chamber within the pump body; a first plunger located at least partially within the pump body and at least partially defining a first drive fluid chamber, the first plunger including a flexible material and configured to expand and compress in a reciprocating action to pump the subject fluid through the first subject fluid chamber within the pump body, and a second plunger located at least partially within the pump body and at least partially defining a second drive fluid chamber, the second plunger including a flexible material and configured to expand and compress in a reciprocating action to pump the subject fluid through the second subject fluid chamber within the pump body. The reciprocating fluid pump may further include an external controller configured to insert drive fluid into the pump body in order to cause the first plunger and the second plunger to move through expansion and compression strokes, wherein the external controller is configured to cause the first plunger and the second plunger to at least partially overlap in timing of the expansion and compression strokes.

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed understanding of the present disclosure, reference should be made to the following detailed description, taken in conjunction with the accompanying drawings, in which like elements have generally been designated with like numerals, and wherein:

FIG. 1 is a perspective view of a reciprocating fluid pump according to an embodiment of the present disclosure;

FIG. 2 is a side cross-sectional view of a reciprocating fluid pump according to an embodiment of the present disclosure;

FIG. 3 is another side cross-sectional view of the reciprocating fluid pump of FIG. 2;

FIG. 4 is a side cross-sectional view of a ball check valve according to one or more embodiments of the present disclosure;

FIG. 5A is a partial cross-sectional view of the reciprocating fluid pump of FIG. 2 according to one or more embodiments of the present disclosure;

FIG. 5B is another partial cross-sectional view of the reciprocating fluid pump of FIG. 2 according to one or more embodiments of the present disclosure; and

FIG. 6 shows two graphs illustrating examples of methods by which some embodiments of reciprocating fluid pumps of the invention may be cycled in a reciprocating action to pump fluid through the pumps.

DETAILED DESCRIPTION

The illustrations presented herein may not be, in some instances, actual views of any particular reciprocating fluid pump or component thereof, but may be merely idealized representations that are employed to describe embodiments of the present invention. Additionally, elements common between figures may retain the same numerical designation.

As used herein, any relational term, such as “first,” “second,” “front,” “back,” etc., is used for clarity and convenience in understanding the disclosure and accompanying drawings, and does not connote or depend on any specific preference or order, except where the context clearly indicates otherwise.

As used herein, the term “substantially” in reference to a given parameter, property, or condition means and includes to a degree that one skilled in the art would understand that the given parameter, property, or condition is met with a small degree of variance, such as within acceptable manufacturing tolerances. For example, a parameter that is substantially met may be at least about 90% met, at least about 95% met, or even at least about 99% met.

Some embodiments of the present disclosure include reciprocating fluid pumps for pumping subject fluids using a pressurized drive fluid. In some embodiments, a reciprocating fluid pump may include a pump body, a first plunger, a second plunger, and an external controller. The first and second plungers may expand and compress longitudinally as the reciprocating fluid pump is cycled during operation thereof. In one or more embodiments, the first and second plungers may not be structurally connected. For instance, the first plunger and the second plunger may not be connected via an interconnecting shaft like conventional reciprocating pumps. Furthermore, a physical motion of one of the plungers does not physically affect the motion of the other plunger. In particular, the motions of the first and second plungers may be independently operated and controlled by the external controller. As a result, the external controller may cause strokes of the first and second plungers to at least partially overlap. Causing the strokes of the first and second plungers to at least partially overlap may provide advantages over conventional fluid pumps. For instance, causing the strokes of the first and second plungers to at least partially overlap may eliminate and/or reduce pulsations in subject fluid flow.

One or more embodiments of the present disclosure include a reciprocating fluid pump having a restricted subject fluid outlet in comparison to a subject fluid inlet. Furthermore, some embodiments of the present disclosure include a reciprocating fluid pump having a first piston and a second piston for at least partially driving the first plunger and the second plunger of the reciprocating fluid pump. The first and second plungers may each include bellows defining a first drive fluid chamber and a second drive fluid chamber. Additionally, the first piston may include a first plurality of vents extending from first drive fluid chamber (i.e., an interior of the bellows of the first plunger) to a first piston chamber, and the second piston may include a second plurality of vents extending from second drive fluid chamber (i.e., an interior of the bellows of the second plunger). Venting the interior of the bellows of the first and second plungers to the first and second piston chambers may also provide advantages over conventional fluid pumps. For example, by allowing the bellows of the first and second plungers to vent through the plurality of vents, the reciprocating fluid pump of the present disclosure may reduce a likelihood that, during a compression stroke, the walls of the bellows of the plungers will bulge (i.e., bend outward) while compressing. Moreover, by allowing the bellows of the first and second plungers to vent through the plurality of vents, the reciprocating fluid pump of the present disclosure may reduce a likelihood that, during an expansion stroke, the walls of the bellows of the plungers will cave (i.e., bend inward) while expanding. As will be understood by one of ordinary skill in the art, by reducing and/or eliminating bulging and caving of the bellows of the plungers during compression and expansion strokes, the reciprocating fluid pump of the present disclosure may greatly reduce wear and tear on the bellows and may lead to longer life spans of the bellows. As a result, the reciprocating fluid pump of the present disclosure may reduce a needed frequency to replace the bellows and may provide cost savings in comparison to conventional reciprocating fluid pumps.

FIG. 1 illustrates an embodiment of a reciprocating fluid pump 100 of the present disclosure. In some embodiments, the reciprocating fluid pump 100 is configured to pump a subject fluid, such as, for example, a liquid (e.g., water, oil, acid, etc.), gas, or powdered substance, using a pressurized drive fluid such as, for example, compressed gas (e.g., air). Thus, in some embodiments, the reciprocating fluid pump 100 may comprise a pneumatically operated fluid pump.

The reciprocating fluid pump 100 includes a pump body 102 that may include two or more components that may be assembled together to form the pump body 102. For example, the pump body 102 may include a center body 104, a first end piece 106 that may be attached to the center body 104 on a first side thereof, and a second end piece 108 that may be attached to the center body 104 on an opposite, second side thereof.

The reciprocating fluid pump 100 may further include a first sensor assembly 109 and a second sensor assembly 111. The first sensor assembly 109 may extend from an exterior of the reciprocating fluid pump 100 and into an interior of the first end piece 106. The second sensor assembly 111 may extend from the exterior of the reciprocating fluid pump 100 and into an interior of the second end piece 108. As is discussed in greater detail below in regard to FIGS. 2-5B, an external controller 170 of the reciprocating fluid pump 100 may utilize the first and second sensor assemblies 109, 111 to operate the reciprocating fluid pump 100.

Referring still to FIG. 1, the reciprocating fluid pump 100 may also include a subject fluid inlet 114 and a subject fluid outlet 116. During operation of the reciprocating fluid pump 100, the reciprocating fluid pump 100 may draw subject fluid into the reciprocating fluid pump 100 through the subject fluid inlet 114 and may expel the subject fluid out from the reciprocating fluid pump 100 through the subject fluid outlet 116. Additionally, the reciprocating fluid pump 100 may a first drive fluid inlet 190 and a second drive fluid inlet 192. As is described in greater detail in regard FIGS. 5A and 5B, the reciprocating fluid pump 100 may insert drive fluid into the first drive fluid inlet 190 and the second drive fluid inlet 192 in order to drive pumping actions of the reciprocating fluid pump 100.

FIG. 2 includes a schematic top cross-sectional view of the reciprocating fluid pump 100 of FIG. 1. As shown in FIG. 2, the pump body 102 may include therein (e.g., may house) a first cavity 110 and a second cavity 112. A first plunger 120 may be disposed within the first cavity 110, and a second plunger 122 may be disposed within the second cavity 112. The first and second plungers 120, 122 may each be formed of and may include a flexible polymer material (e.g., an elastomer or a thermoplastic material). As is discussed in further detail below, each of the first and second plungers 120, 122 may comprise, for example, a diaphragm and/or a bellows (as shown in the figures). Furthermore, the first and second plungers 120, 122 may expand and compress longitudinally as the reciprocating fluid pump 100 is cycled (i.e., in the left and right horizontal directions from the view shown in FIG. 2) during operation thereof.

The first plunger 120 may divide the first cavity 110 into a first subject fluid chamber 126 on a first side of the first plunger 120 and a first drive fluid chamber 127 on an opposite, second side of the first plunger 120 (e.g., within a bellows of the first plunger 120). Similarly, the second plunger 122 may divide the second cavity 112 into a second subject fluid chamber 128 on a first side of the second plunger 122 and a second drive fluid chamber 129 on an opposite, second side of the second plunger 122 (e.g., within a bellows of the second plunger 122).

A peripheral edge 123 of the first plunger 120 may be attached to the pump body 102, and a fluid tight seal may be provided between the pump body 102 and the first plunger 120. Similarly, a peripheral edge 125 of the second plunger 122 may be attached to the pump body 102, and a fluid tight seal may be provided between the pump body 102 and the second plunger 122.

FIG. 3 shows a schematic cross-sectional view of the reciprocating fluid pump 100 of FIGS. 1 and 2. The view shown in FIG. 3 is orthogonal to the view shown in FIG. 2. Referring to FIGS. 2 and 3 together, the pump body 102 may include a first subject fluid inlet 130 that leads from the subject fluid inlet 114 and into the first subject fluid chamber 126 through the pump body 102, and the pump body 102 may include a first subject fluid outlet 134 that leads out from the first subject fluid chamber 126 and to the subject fluid outlet 116 through the pump body 102. Similarly, the pump body 102 may include a second subject fluid inlet 132 that leads from the subject fluid inlet 114 and into the second subject fluid chamber 128 through the pump body 102, and the pump body 102 may include a second subject fluid outlet 136 that leads out from the second subject fluid chamber 128 and to the subject fluid outlet 116 through the pump body 102. Accordingly, subject fluid may be drawn into the reciprocating fluid pump 100 through the subject fluid inlet 114 from a single fluid source, and subject fluid may be expelled from the reciprocating fluid pump 100 through the subject fluid outlet 116.

Furthermore, the reciprocating fluid pump 100 may include a first subject fluid inlet check valve 131, a first subject fluid outlet check valve 135, a second subject fluid inlet check valve 133, and a second subject fluid outlet check valve 137. The first subject fluid inlet check valve 131 may be provided proximate the first subject fluid inlet 130 to ensure that fluid is capable of flowing into the first subject fluid chamber 126 through the first subject fluid inlet 130, but incapable of flowing out from the first subject fluid chamber 126 through the first subject fluid inlet 130. The first subject fluid outlet check valve 135 may be provided proximate the first subject fluid outlet 134 to ensure that fluid is capable of flowing out from the first subject fluid chamber 126 through the first subject fluid outlet 134, but incapable of flowing into the first subject fluid chamber 126 through the first subject fluid outlet 134. Similarly, the second subject fluid inlet check valve 133 may be provided proximate the second subject fluid inlet 132 to ensure that fluid is capable of flowing into the second subject fluid chamber 128 through the second subject fluid inlet 132, but incapable of flowing out from the second subject fluid chamber 128 through the second subject fluid inlet 132. The second subject fluid outlet check valve 137 may be provided proximate the second subject fluid outlet 136 to ensure that fluid is capable of flowing out from the second subject fluid chamber 128 through the second subject fluid outlet 136, but incapable of flowing into the second subject fluid chamber 128 through the second subject fluid outlet 136. Each of the check valves 131, 133, 135, and 137 may include any suitable valve that allows flow in one direction and restricts flow in an opposite direction, such as, for example, a ball check valve, a diaphragm check valve, a magnet check valve, etc.

In some embodiments, the subject fluid outlet 116 of the reciprocating fluid pump 100 may be restricted in comparison to the subject fluid inlet 114 of the reciprocating fluid pump 100. For example, the subject fluid outlet 116 may have a smaller diameter in comparison to the subject fluid inlet 114. The restricted subject fluid outlet 116 may enable the reciprocating fluid pump 100 to provide a particular fluid flow out of the reciprocating fluid pump 100. For instance, in one or more embodiments, restricted subject fluid outlet 116 may enable the reciprocating fluid pump 100 to provide a reduced (e.g., slower) fluid flow in comparison to conventional reciprocating fluid pumps. Furthermore, a particular (e.g., a desired) fluid flow may be achieved by selecting a particular diameter of the subject fluid outlet 116 in comparison to the diameter of the subject fluid inlet 114.

FIG. 4 shows an embodiment of a ball check valve 430 of the present disclosure that restricts flow in at least one direction. The ball check valve 430 may include a valve housing 432 with a valve seat 433. A ball 434 may be configured to seal against the valve seat 433 of the valve housing 432 to restrict flow through the valve housing 432 in at least one direction (e.g., from right to left in the perspective of FIG. 4). For example, when sufficient fluid pressure is present on the left side (from the perspective of FIG. 4) of the ball 434, the ball 434 may be forced away from the valve seat 433 to open the ball check valve 430 and allow flow therethrough. On the other hand, when sufficient fluid pressure is present on the right side (from the perspective of FIG. 4) of the ball 434, the ball 434 may be forced against the valve seat 433 and may seal against the valve seat 433 again. In this manner, the ball check valve 430 may work to restrict flow through the ball check valve 430 from the right to the left (from the perspective of FIG. 4).

FIG. 5A shows an enlarged view of a portion of FIG. 2 including the first end piece 106 of the reciprocating fluid pump 100. FIG. 5B shows an enlarged view of a portion of FIG. 2 including the second end piece 108 of the reciprocating fluid pump 100. Referring to FIGS. 5A and 5B together, the reciprocating fluid pump 100 may include a first piston 140, a second piston 142, a first piston chamber 144, and a second piston chamber 146. The first piston 140 may include a first piston head 148 and a first shaft 150. The second piston 142 may include a second piston head 152 and a second shaft 154.

The first piston head 148 may divide the first piston chamber 144 into a first portion 156 and a second portion 158. Additionally, the first shaft 150 may extend from the first piston head 148 on one longitudinal end and may be coupled to the first plunger 120 on a second opposite longitudinal end. The first shaft 150 may be coupled to a side of the first plunger 120 facing the first drive fluid chamber 127. For example, the first shaft 150 may extend from the first piston head 148, through a first bearing surface 159 of the first end piece 106 between the first piston chamber 144 and the first drive fluid chamber 127, and into the first plunger 120 (e.g., through a bellows of the first plunger 120 and at least partially into the first plunger 120).

The second piston head 152 may also divide the second piston chamber 146 into a first portion 160 and a second portion 162. Furthermore, the second shaft 154 may extend from the second piston head 152 on one longitudinal end and may be coupled to the second plunger 122 on a second opposite longitudinal end. The second shaft 154 may be coupled to a side of the second plunger 122 facing the second drive fluid chamber 129. For example, the second shaft 154 may extend from the second piston head 152, through a second bearing surface 163 of the second end piece 108 between the second piston chamber 146 and the second drive fluid chamber 129, and into the second plunger 122 (e.g., through a bellows of the second plunger 122 and at least partially into the second plunger 122).

Furthermore, the first shaft 150 of the first piston 140 and the second shaft 154 of the second piston 142 may not be connected via an interconnecting shaft like conventional reciprocating pumps. Put another way, the first plunger 120 may not be structurally coupled (i.e., connected) to the second plunger 122. Rather, the first and second plungers 120, 122 may be distinct from one another. For example, a physical motion of one of the plungers does not physically affect the motion of the other plunger. In particular, the motions of the first and second plungers 120, 122 may be individually operated and controlled by the external controller 170, as is discussed in further detail below. In other words, the first plunger 120 and the second plunger 122 are independently movable during operation (e.g., independently operated). As is described in further detail below in regard to FIG. 6, having the first and second plungers 120, 122 being structurally unconnected may allow the external controller 170 to independently operate to the first and second plungers 120, 122 and to cause strokes of the first and second plungers 120, 122 to at least partially overlap.

Referring still to FIGS. 5A and 5B, in some embodiments, the first shaft 150 of the first piston 140 may include a first sensor-receiving cavity 164. The first sensor-receiving cavity 164 may extend from the first piston head 148 and at least partially through the first shaft 150. Additionally, the second shaft 154 of the second piston 142 may include a second sensor-receiving cavity 166. The second sensor-receiving cavity 166 may extend from the second piston head 152 and at least partially through the second shaft 154. The first and second sensor-receiving cavities 164, 166 may be sized and shaped to receive at least a portion of the first and second sensor assemblies 109, 111, respectively.

In some embodiments, the first sensor assembly 109 may include a first sensor portion 182 and a first target portion 184. The first sensor portion 182 may be disposed within and may extend through the first piston chamber 144. Furthermore, the first sensor portion 182 may extend at least partially into the first sensor-receiving cavity 164 of the first shaft 150 of the first piston 140. The first target portion 184 of the first sensor assembly 109 may be disposed in a base (i.e., an interior end) of the first sensor receiving cavity 164. The first sensor portion 182 may be configured to determine a proximity of the first sensor portion 182 to the first target portion 184.

Additionally, in some embodiments, the second sensor assembly 111 may include a second sensor portion 186 and a second target portion 188. The second sensor portion 186 may be disposed within and may extend through the second piston chamber 146. Furthermore, the second sensor portion 186 may extend at least partially into the second sensor receiving cavity 166 of the second shaft 154 of the second piston 142. The second target portion 188 of the second sensor assembly 111 may be disposed within a base (i.e., an interior end) of the second sensor receiving cavity 166. The second sensor portion 186 may be configured to determine a proximity of the second sensor portion 186 to the second target portion 188.

In some embodiments, the first and second sensor assemblies 109, 111 may include magnetic proximity sensors and targets. In additional embodiments, the first and second sensor assemblies 109, 111 may include inductive proximity sensors and targets. In further embodiments, the first and second sensor assemblies 109, 111 may include optical proximity sensors and targets.

In one or more embodiments, the first shaft 150 of the first piston 140 may include a first plurality of vents 168 extending from the first drive fluid chamber 127 (i.e., an interior of the bellows of the first plunger 120) to the first sensor receiving cavity 164 of the first shaft 150 of the first piston 140. For example, the first plurality of vents 168 may connect the first drive fluid chamber 127 to the first portion 156 of the first piston chamber 144. Additionally, the second shaft 154 of the second piston 142 may include a second plurality of vents 172 extending from the second drive fluid chamber 129 (i.e., an interior of the bellows of the second plunger 122) to the second sensor-receiving cavity 166 of the second shaft 154 of the second piston 142. For example, the second plurality of vents 172 may connect the second drive fluid chamber 129 to the first portion 160 of the second piston chamber 146.

The first and second pluralities of vents 168, 172 (referred to collectively as the plurality of vents) may provide advantages over conventional reciprocating fluid pumps. For example, by allowing the bellows of the first and second plungers 120, 122 to vent through the plurality of vents, the reciprocating fluid pump 100 of the present disclosure may reduce a likelihood that, during a compression stroke, the walls of the bellows of the first and second plungers 120, 122 will bulge (i.e., bend outward). Moreover, by allowing the bellows of the first and second plungers 120, 122 to vent through the plurality of vents, the reciprocating fluid pump 100 of the present disclosure may reduce a likelihood that, during an expansion stroke, the walls of the bellows of the first and second plungers 120, 122 will cave (i.e., bend inward). As will be understood by one of ordinary skill in the art, by reducing and/or eliminating bulging and caving of the bellows of the first and second plungers 120, 122 during compression and expansion strokes, the reciprocating fluid pump 100 of the present disclosure may greatly reduce wear and tear on the bellows and may lead to longer life spans of the bellows. As a result, the reciprocating fluid pump 100 of the present disclosure may reduce a needed frequency to replace the bellows and may provide cost savings in comparison to conventional reciprocating fluid pumps.

Referring still to FIGS. 5A and 5B, in some embodiments, the first end piece 106 may include a first vent 174 extending through a wall of the first end piece 106. Additionally, the first end piece 106 may also include a first drive fluid outlet 176 extending through the wall of the first end piece 106. The first vent 174 may provide a drive fluid flow path to the second portion 158 of the first piston chamber 144. As will be understood by one of ordinary skill in the art, supplying drive fluid to the second portion 158 of the first piston chamber 144 will drive the first piston 148 leftward from the perspective of FIG. 5A. Additionally, the first drive fluid chamber 127 may be supplied with drive fluid through the first drive fluid inlet 190 (FIG. 1). As will be understood by one of ordinary skill in the art, supplying drive fluid to the first drive fluid chamber 127 will cause the bellows of the first plunger 120 to expand and drive the first plunger 120 rightward from the perspective of FIG. 5A. Furthermore, as is discussed in greater detail below, in some instances, the first vent 174 may serve as a drive fluid outlet for the second portion 158 of the first piston chamber 144. Moreover, the first drive fluid outlet 176 may provide a fluid flow path to the first portion 156 of the first piston chamber 144. In some embodiments, the first drive fluid outlet 176 may serve as a drive fluid inlet (e.g., a vent) for the first portion 156 of the first piston chamber 144.

Furthermore, the second end piece 108 may include a second vent 178 extending through a wall of the second end piece 108. Additionally, the second end piece 108 may also include a second drive fluid outlet 180 extending through the wall of the second end piece 108. The second vent 178 may provide a drive fluid flow path to the second portion 162 of the second piston chamber 146. As will be understood by one of ordinary skill in the art, supplying drive fluid to the second portion 162 of the second piston chamber 146 will drive the second piston 152 rightward from the perspective of FIG. 5A. Additionally, the second drive fluid chamber 129 may be supplied with drive fluid through the second drive fluid inlet 192 (FIG. 1). As will be understood by one of ordinary skill in the art, supplying drive fluid to the second drive fluid chamber 129 will cause the bellows of the second plunger 122 to expand and drive the second plunger 122 leftward from the perspective of FIG. 5A. Furthermore, as is discussed in greater detail below, in some instances, the second vent 178 may serve as a drive fluid outlet for the second portion 162 of the second piston chamber 146. Additionally, the second drive fluid outlet 180 may provide a fluid flow path to the first portion 160 of the second piston chamber 146. In some embodiments, the second drive fluid outlet 180 may serve as a drive fluid inlet (e.g., vent) for the first portion 160 of the second piston chamber 146.

Referring to FIGS. 2 and 3 again, during operation, the first plunger 120 is capable of expanding in the rightward direction and compressing in the leftward direction from the perspective of FIG. 2. Similarly, the second plunger 122 is capable of expanding in the leftward direction and compressing in the rightward direction from the perspective of FIG. 2. Put another way, the first and second plungers 120, 122 may cycle through compression and expansion strokes during operation.

As the first plunger 120 expands (i.e., moves through an expansion stroke) and the second plunger 122 compresses (i.e., moves through a compressions stroke), a volume of the first drive fluid chamber 127 increases, a volume of the first subject fluid chamber 126 decreases, a volume of the second subject fluid chamber 128 increases, and a volume of the second drive fluid chamber 129 decreases. As a result, subject fluid may be expelled from the first subject fluid chamber 126 through the first subject fluid outlet 134, and subject fluid may be drawn into the second subject fluid chamber 128 through the second subject fluid inlet 132. The first plunger 120 may be extended at least partially by providing pressurized drive fluid within the first drive fluid chamber 127. Furthermore, the second plunger 122 may be compressed by providing pressurized drive fluid within the second portion 162 of the second piston chamber 146.

Conversely, as the second plunger 122 expands (i.e., moves through an expansion stroke) and the first plunger 120 compresses (i.e., moves through a compression stroke), the volume of the second drive fluid chamber 129 increases, the volume of the second subject fluid chamber 128 decreases, the volume of the first subject fluid chamber 126 increases, and the volume of the first drive fluid chamber 127 decreases. As a result, subject fluid may be expelled from the second subject fluid chamber 128 through the second subject fluid outlet 136, and subject fluid may be drawn into the first subject fluid chamber 126 through the first subject fluid inlet 130. The second plunger 122 may be extended at least partially by providing pressurized drive fluid within the second drive fluid chamber 129. As is discussed in greater detail below, compression and expansion of the first and second plungers 120, 122 may be controlled by an external controller 170.

Referring to FIGS. 1, 2, 5A, and 5B together, in order to commence an expansion stroke of the first plunger 120, pressurized drive fluid may be inserted through the first drive fluid inlet 190 of the first end piece 106 of the reciprocating fluid pump 100. For example, in some instances, pressurized drive fluid may be inserted through the first drive fluid inlet 190 into the first drive fluid chamber 127. In other embodiments, pressurized drive fluid may be inserted through first drive fluid inlet 190 and through the vent 176 in order to have amplified pressure of more than 1-1 drive fluid to subject fluid 126. As will be understood by one of ordinary skill in the art, an amount of amplification would be determined by a volume of chamber 144. Regardless, the first drive fluid chamber 127 and the first portion 156 of the first piston chamber 144 may be pressurized with the pressurized drive fluid, which may cause the first plunger 120 to commence an expansion stroke. Put another way, pressurizing the first drive fluid chamber 127 and the first portion 156 of the first piston chamber 144 may cause the first plunger 120 (and the bellows of the first plunger 120) to expand.

As the first plunger 120 moves through an expansion stroke, subject fluid within the first subject fluid chamber 126 may be expelled from the first subject fluid chamber 126, through the first subject fluid outlet 134, and through the subject fluid outlet 116. As is discussed below, at least substantially at the same time, subject fluid may be drawn into the second subject fluid chamber 128 through the second subject fluid inlet 132.

After expelling the subject fluid from the first subject fluid chamber 126, in order to commence a compression stroke of the first plunger 120, the first drive fluid chamber 127 may be depressurized (e.g., vented to ambient, a reduced pressure area, or a vacuum). Additionally, pressurized drive fluid may be inserted through the first vent 174 and into the second portion 158 of the first piston chamber 144. As a result, the second portion 158 of the first piston chamber 144 may be pressurized with the pressurized drive fluid, which may cause the first plunger 120 to commence a compression stroke. Put another way, pressurizing the second portion 158 of the first piston chamber 144 and depressurizing the first portion 156 of the first piston chamber 144 (in embodiments with amplified drive fluid) and the first drive fluid chamber 127 the may cause the first plunger 120 (and the bellows of the first plunger 120) to compress.

As the first plunger 120 moves through a compression stroke, subject fluid may be drawn through the first subject fluid inlet 130 and into the first subject fluid chamber 126. As is discussed below, at least substantially at the same time, subject fluid may be expelled from the second subject fluid chamber 128 and through the second subject fluid outlet 136.

In order to commence an expansion stroke of the second plunger 122, pressurized drive fluid may be inserted through the second drive fluid inlet 192 of the second end piece 108 of the reciprocating fluid pump 100. For example, in some instances, pressurized drive fluid may be inserted through the second drive fluid inlet 192 into the second drive fluid chamber 129. In other embodiments, pressurized drive fluid may be inserted through second drive fluid inlet 192 and through the second vent 178 in order to have amplified pressure of more than 1-1 drive fluid to subject fluid 126. As will be understood by one of ordinary skill in the art, an amount of amplification would be determined by a volume of chamber 146. Regardless, the second drive fluid chamber 129 and the first portion 160 of the second piston chamber 146 may be pressurized with the pressurized drive fluid, which may cause the second plunger 122 to commence an expansion stroke. Put another way, pressurizing the second drive fluid chamber 129 and the first portion 160 of the second piston chamber 146 may cause the second plunger 122 (and the bellows of the second plunger 122) to expand.

As the second plunger 122 moves through an expansion stroke, subject fluid within the second subject fluid chamber 128 may be expelled from the second subject fluid chamber 128, through the second subject fluid outlet 136, and through the subject fluid outlet 116. As is discussed above, at least substantially at the same time, subject fluid may be drawn into the first subject fluid chamber 126 through the first subject fluid inlet 130.

After expelling the subject fluid from the second subject fluid chamber 128, in order to commence a compressions stroke of the second plunger 122, the second drive fluid chamber 129 may be depressurized (e.g., vented to ambient, a reduced pressure, or even a vacuum). Additionally, pressurized drive fluid may be inserted through the second vent 178 and into the second portion 162 of the second piston chamber 146. As a result, the second portion 162 of the second piston chamber 146 may be pressurized with the pressurized drive fluid, which may cause the second plunger 122 to commence a compression stroke. Put another way, pressurizing the second portion 158 of the first piston chamber 144 and depressurizing the first portion 160 of the second piston chamber 146 (in embodiments with amplified drive fluid) and the second drive fluid chamber 129 may cause the second plunger 122 (and the bellows of the second plunger 122) to compress.

As the second plunger 122 moves through a compression stroke, subject fluid may be drawn through the second subject fluid inlet 132 and into the second subject fluid chamber 128. As is discussed above, at least substantially at the same time, subject fluid may be expelled from the first subject fluid chamber 126 and through the first subject fluid outlet 134.

Thus, to drive the pumping action of the reciprocating fluid pump 100, the first drive fluid chamber 127 and the second drive fluid chamber 129 may be pressurized in an alternating or cyclic manner to cause the first plunger 120 and the second plunger 122 to reciprocate back and forth (e.g., move through sequential expansion and compression strokes) within the pump body 102, as discussed above.

In some embodiments, as will be understood by one of ordinary skill in the art, the reciprocating fluid pump 100 may comprise a shifting mechanism for shifting the flow of pressurized drive fluid back and forth between the first drive fluid chamber 127 and the second drive fluid chamber 129. In some instances, the shifting mechanism may comprise, for example, the first and second pistons 140, 142 and a shuttle valve. For example, the reciprocating fluid pump 100 may include a shuttle valve assembly as described in U.S. patent application Ser. No. 13/228,934, to Simmons et al., filed Sep. 9, 2011, the disclosure of which is incorporated in its entirety by reference herein.

Referring to FIG. 2 again, as noted above, in one or more embodiments, the pumping action (e.g., the expansion and compression strokes of the first and second plungers 120, 122) may be operated by the external controller 170. In particular, the external controller 170 may be operably coupled to a drive fluid source (e.g., a source of compressed air) and may control when and where drive fluid is inserted into the reciprocating fluid pump 100. In some embodiments, the external controller 170 may include a programmable logic controller (PLC). For instance, the external controller 170 may include a digital computer that has been ruggedized and adapted for controlling processes (e.g., pumping fluid). In some embodiments, the external controller 170 can include a RIO-47100 made by GALIL™ or any other PLC known in the art.

In one or more embodiments, the external controller 170 may be operably coupled to the first sensor assembly 109 and the second sensor assembly 111 of the reciprocating fluid pump 100. As mentioned above, the first sensor assembly 109 may be disposed within the first end piece 106 of the reciprocating fluid pump 100, and the second sensor assembly 111 may be disposed within the second end piece 108 of the reciprocating fluid pump 100. Furthermore, as discussed above, the first and second sensor portions of the first and second sensor assemblies 109, 111 are configured to determine proximities of the first and second sensor portions to the first and second target portions, respectively.

Based on the determined proximity of the first sensor portion 182 to the first target portion 184 and the determined proximity of the second sensor portion 186 to the second target portion 188, the external controller 170 may operate the expansion and compression strokes of the first plunger 120 and the second plunger 122. For example, during a pumping action of the reciprocating fluid pump 100, the external controller 170 may utilize the first and second sensor assemblies 109, 111 to sense the ends of expansion and compression strokes of the first plunger 120 and the second plunger 122. For instance, when the external controller 170 senses (via the first sensor assembly 109) that the first sensor portion 182 of the first sensor assembly 109 is in most proximate position relative to the first target portion 184 of the first sensor assembly 109, the external controller 170 may determine that the first plunger 120 is at an end of a compression stroke. Furthermore, based on determining that the first plunger 120 is at an end of a compression stroke, the external controller 170 can cause the second portion 158 of the first piston chamber 144 to be depressurized and can cause pressurized drive fluid to be inserted into the first drive fluid chamber 127 in order to commence an expansion stroke of the first plunger 120.

Conversely, when the external controller 170 senses (via the first sensor assembly 109) that the first sensor portion 182 of the first sensor assembly 109 in a least proximate (i.e., most distant) position relative to the first target portion 184 of the first sensor assembly 109, the external controller 170 may determine that the first plunger 120 is at an end of an expansion stroke, the external controller 170 can cause the first drive fluid chamber 127 to be depressurized and can cause pressurized drive fluid to be inserted into the second portion 158 of the first piston chamber 144 to commence an compression stroke of the first plunger 120. Furthermore, the external controller 170 may utilize the second sensor assembly 111 in a similar manner to move the second plunger 122 through expansion and compression strokes.

As noted above, the external controller 170 may be used to overlap the timing of the strokes (i.e., compression strokes and/or expansion strokes) of the first plunger 120 and the second plunger 122 to reduce and/or eliminate undesired pulsations in fluid flow. Such operation is further described with reference to FIG. 6, which includes two graphs of pressure as a function of time. The graph shown at the top of FIG. 6 represents the pressure P₁₂₇ of the first drive fluid chamber 127 as a function of time, and the graph shown at the bottom of FIG. 6 represents the pressure P₁₂₉ of the second drive fluid chamber 129 over the same period of time represented in the graph at the top of FIG. 6.

Referring to FIGS. 2 and 6 together, at time t₀, the pressure within the first drive fluid chamber 127 may be at an elevated pressure P₀, and the pressure within the second drive fluid chamber 129 may be at a reduced pressure P₀ (e.g., atmospheric pressure). At time t₁, the second plunger 122 (FIG. 2) may reach the end of a compression stroke, and the second drive fluid chamber 129 may be pressurized to the elevated pressure P₁. At a later time t₂, after a time period Δt corresponding to the difference between the phases of the two cycles, the first plunger 120 may reach the end of an extension stroke, and the first drive fluid chamber 127 may be vented to the reduced pressure P₀. In some embodiments, Δt may be within a range of about 0.25 seconds to about 60 seconds. Furthermore, in some embodiments, Δt may include between about 5.0% and about 20% of a duration of time of an overall cycle (e.g., a compression stroke and an expansion stroke of both plungers) of the reciprocating fluid pump 100. For instance, Δt may include about 10.0% of a duration of time of an overall cycle of the reciprocating fluid pump 100.

From time t₁ to time t₂, both the first drive fluid chamber 127 and the second drive fluid chamber 129 may be at the elevated pressure P₁. At time t₂, the first drive fluid chamber 127 may be depressurized to reduced pressure P₀. At time t₃, the first drive fluid chamber 127 may be pressurized to elevated pressure P₁. From time t₃ to time t₄, both the first drive fluid chamber 127 and the second drive fluid chamber 129 may be at the elevated pressure P₁. At time t₄, the second drive fluid chamber 129 may be depressurized to reduced pressure P₀. At time t₄, the second drive fluid chamber 129 may be pressurized to elevated pressure P₁. The time period extending from time t₁ to time t₅ represents one complete cycle of the second plunger 122. At time t₆, the first drive fluid chamber 127 may again be depressurized to the reduced pressure P₀. The time period extending from time t₂ to time t₆ represents one complete cycle of the first plunger 120.

Furthermore, as shown in FIG. 6, expansion strokes of the first plunger 120 and the second plunger 122 may at least partially overlap in order to reduce and/or eliminate undesired pulsations in fluid flow. Thus, as described above, in accordance with some embodiments of the invention, the first plunger 120 and the second plunger 122 in the reciprocating fluid pump 100 may be operated asynchronously with one another. In additional embodiments, however, the first and second plungers 120, 122 may expand and compress synchronously, either in phase with one another or out of phase with one another. For example, the first and second plungers 120, 122 may operate synchronously, but out of phase from one another by 180°.

Although the reciprocating fluid pump 100 of FIGS. 1, 2, 4, 5A, and 5B is shown as employing two plungers, additional embodiments of fluid pumps of the present invention may only include a single plunger, or may include more than two plungers. Furthermore, although the reciprocating fluid pump 100 of FIGS. 1, 2, 4, and 5 is shown with plungers at least partially internal to a pump body 102, additional embodiments of reciprocating fluid pumps of the present invention may include reciprocating fluid pumps with one or more plungers, diaphragms, and/or bellows positioned at least partially external to a pump body 102.

The embodiments of the disclosure described above and illustrated in the accompanying drawings do not limit the scope of the disclosure, which is encompassed by the scope of the appended claims and their legal equivalents. Any equivalent embodiments are within the scope of this disclosure. Indeed, various modifications of the disclosure, in addition to those shown and described herein, such as alternative useful combinations of the elements described, will become apparent to those skilled in the art from the description. Such modifications and embodiments also fall within the scope of the appended claims and equivalents. 

What is claimed is:
 1. A reciprocating fluid pump for pumping a subject fluid, comprising: a pump body; a first subject fluid chamber within the pump body; a second subject fluid chamber within the pump body; a first plunger located at least partially within the pump body and at least partially defining a first drive fluid chamber, the first plunger comprising a flexible material and configured to expand and compress in a reciprocating action to pump the subject fluid through the first subject fluid chamber within the pump body; a second plunger located at least partially within the pump body and at least partially defining a second drive fluid chamber, the second plunger comprising a flexible material and configured to expand and compress in a reciprocating action to pump the subject fluid through the second subject fluid chamber within the pump body, wherein the first plunger is not structurally coupled to the second plunger, such that the first plunger and the second plunger are independently movable during operation; a first sensor assembly at least partially disposed within the pump body and configured to sense a position of the first plunger; a second sensor assembly at least partially disposed within the pump body and configured to sense a position of the second plunger; and an external controller operably coupled to the first sensor assembly and the second sensor assembly and configured to insert drive fluid into the pump body based on sensed positions of the first plunger and the second plunger.
 2. The reciprocating fluid pump of claim 1, further comprising: a first piston chamber formed within the pump body and adjacent to the first drive fluid chamber; a second piston chamber formed within the pump body and adjacent to the second drive fluid chamber; a first piston comprising a first piston head and a first shaft extending from the first piston head, wherein the first piston head is disposed within the first piston chamber and wherein the first shaft is coupled to the first plunger and extends between the first drive fluid chamber and the first piston chamber; and a second piston comprising a second piston head and a second shaft extending from the second piston head, wherein the second piston head is disposed within the second piston chamber and wherein the second shaft is coupled to the second plunger and extends between the second drive fluid chamber and the second piston chamber.
 3. The reciprocating fluid pump of claim 2, wherein the first piston comprises a first sensor-receiving cavity extending from the first piston head of the first piston and at least partially through the first shaft of the first piston, and wherein the second piston comprises a second sensor-receiving cavity extending from the second piston head of the second piston and at least partially through the second shaft of the second piston.
 4. The reciprocating fluid pump of claim 3, wherein the first sensor assembly comprises: a first sensor portion extending at least partially into the first sensor-receiving cavity; and a first target portion disposed within a base of the first sensor-receiving cavity.
 5. The reciprocating fluid pump of claim 1, wherein the first sensor assembly comprises an inductive proximity sensor and a target portion.
 6. The reciprocating fluid pump of claim 1, wherein the external controller comprises a programmable logic controller.
 7. The reciprocating fluid pump of claim 1, further comprising: a subject fluid inlet extending from an exterior of the pump body and into the first and second subject fluid chambers; and a subject fluid outlet extending from the first and second subject fluid chambers and to the exterior of the pump body, wherein the subject fluid outlet is restricted comparative to the subject fluid inlet.
 8. A reciprocating fluid pump for pumping a subject fluid, comprising: a pump body; a first subject fluid chamber within the pump body; a second subject fluid chamber within the pump body; a first plunger located at least partially within the pump body, the first plunger comprising a flexible material and configured to expand and compress in a reciprocating action to pump the subject fluid through the first subject fluid chamber within the pump body; a second plunger located at least partially within the pump body, the second plunger comprising a flexible material and configured to expand and compress in a reciprocating action to pump the subject fluid through the second subject fluid chamber within the pump body; a first drive fluid chamber at least partially defined within bellows of the first plunger; a second drive fluid chamber at least partially defined within bellows of the second plunger; a first piston chamber formed within the pump body and adjacent to the first drive fluid chamber; a second piston chamber formed within the pump body and adjacent to the second drive fluid chamber; a first piston coupled to the first plunger and extending between the first drive fluid chamber and the first piston chamber, the first piston comprising a first plurality of vents extending through the first piston and from the first drive fluid chamber to the first piston chamber; and a second piston coupled to the second plunger and extending between the second drive fluid chamber and the second piston chamber, the second piston comprising a second plurality of vents extending through the second piston and from the second drive fluid chamber to the second piston chamber.
 9. The reciprocating fluid pump of claim 8, further comprising: a first sensor assembly at least partially disposed within the pump body and configured to sense a position of the first plunger; a second sensor assembly at least partially disposed within the pump body and configured to sense a position of the second plunger; and an external controller operably coupled to the first sensor assembly and the second sensor assembly and configured to insert drive fluid into the pump body based on sensed positions of the first plunger and the second plunger.
 10. The reciprocating fluid pump of claim 9, wherein the first sensor assembly comprises: a first sensor portion extending at least partially through a portion of the first piston; and a first target portion disposed within the first piston.
 11. The reciprocating fluid pump of claim 10, wherein the first piston comprises a first piston head and a first shaft extending from the first piston head, wherein the first piston head is disposed within the first piston chamber and wherein the first shaft of the first piston is coupled to the first plunger and extends between the first drive fluid chamber and the first piston chamber.
 12. The reciprocating fluid pump of claim 8, further comprising: a subject fluid inlet extending from an exterior of the pump body and into the first and second subject fluid chambers; and a subject fluid outlet extending from the first and second subject fluid chambers and to the exterior of the pump body, wherein the subject fluid outlet is restricted comparative to the subject fluid inlet.
 13. The reciprocating fluid pump of claim 8, wherein the first plunger and the second plunger are not structurally connected.
 14. The reciprocating fluid pump of claim 8, wherein the pump body comprises: a center body at least partially housing the first and second subject fluid chambers; a first end piece attached to the center body on a first side of the center body and housing the first piston chamber; and a second end piece attached to the center body on a second side of the center body and housing the second piston chamber.
 15. A reciprocating fluid pump for pumping a subject fluid, comprising: a pump body; a first subject fluid chamber within the pump body; a second subject fluid chamber within the pump body; a first plunger located at least partially within the pump body and at least partially defining a first drive fluid chamber, the first plunger comprising a flexible material and configured to expand and compress in a reciprocating action to pump the subject fluid through the first subject fluid chamber within the pump body; a second plunger located at least partially within the pump body and at least partially defining a second drive fluid chamber, the second plunger comprising a flexible material and configured to expand and compress in a reciprocating action to pump the subject fluid through the second subject fluid chamber within the pump body; and an external controller configured to insert drive fluid into the pump body in order to cause the first plunger and the second plunger to move through expansion and compression strokes, wherein the external controller is configured to cause the first plunger and the second plunger to at least partially overlap in timing of the expansion and compression strokes.
 16. The reciprocating fluid pump of claim 15, further comprising: a first piston chamber formed within the pump body and adjacent to the first drive fluid chamber; a second piston chamber formed within the pump body and adjacent to the second drive fluid chamber; a first piston comprising a first piston head and a first shaft extending from the first piston head, wherein the first piston head is disposed within the first piston chamber and wherein the first shaft is coupled to the first plunger and extends between the first drive fluid chamber and the first piston chamber; a second piston comprising a second piston head and a second shaft extending from the second piston head, wherein the second piston head is disposed within the second piston chamber and wherein the second shaft is coupled to the second plunger and extends between the second drive fluid chamber and the second piston chamber.
 17. The reciprocating fluid pump of claim 16, wherein the first piston comprises a first plurality of vents extending through the first piston and from the first drive fluid chamber to the first piston chamber, and wherein the second piston comprises a second plurality of vents extending through the second piston and from the second drive fluid chamber to the second piston chamber.
 18. The reciprocating fluid pump of claim 15, further comprising: a first sensor assembly at least partially disposed within the pump body and configured to sense a position of the first plunger; and a second sensor assembly at least partially disposed within the pump body and configured to sense a position of the second plunger, wherein the external controller operably coupled to the first sensor assembly and the second sensor assembly and configured to insert drive fluid into the pump body and drive the first plunger and the second plunger based on sensed positions of the first plunger and the second plunger.
 19. The reciprocating fluid pump of claim 15, wherein the first plunger and the second plunger are not structurally connected.
 20. The reciprocating fluid pump of claim 15, 